BK80: Identify a Component

[lothian]

Working down a punchlist of issues in my new ancient Black Knight 1980 (BK80)

What is the beat up widget shown in the image below? Clearly it's a load interference filter from a Mexican assembly line. But what is it?
Even better for my purposes: What is the exact part number of its functional replacement, and where does one order the thing?

 

[luch]

https://www.marcospecialties.com/pinball-parts/EL50

 

[lothian]

Thanks, mightily!

 

[necro_nemesis]

High frequency filter between mains and machine and vice versa. It associated with a varistor and fuse on that circuit if you're trying to troubleshoot a mains power issue.

 

[sylvain]

This part fails very rarely in pinball machines.
Just curious, what issue are you trying to solve by replacing that part?

 

[lothian]

I'm t'shooting two items concurrently on my list of issues with this BK80: A half-a-second 60hz sound burst at power on, and flickering (LED) lights on the house mains circuit during game play.

Now that I know what that line filter is intended to do, it seems unlikely that thing is causing/contributing to the former; while it may be the reason for the latter. I'm not keen on firing the parts cannon at this game in lieu of confirming a faulty component. But it sure is handy to swap in known-good parts to rule out a suspect.

 

[necro_nemesis]

Suggest YouTube search for a few System 6 or 7 pinball vids and a scan through the videos to the point of machine power on to confirm what you are hearing. It's probably not a failure but a "feature" you're hearing. Not necessarily a wanted feature...

 

[sylvain]

From the description of the issues, it does not appear this part is the culprit. No point replacing it in my experience.

As mentioned by necro_nemesis above, most Williams pinball machines from that era have a loud short buzz at power-up. Design limitation it seems, as I have observed that the buzz on power-up is still present at power-up even after recapping the sound board and power supply.

For the LEDs flashing during game play, it is often due to the limited power of the game power transformer when flipping. Secondary voltages dip down shortly during that time, and lamps would reflect that. The blinking is typically worse when using a long extension cord. The quick dimming/flickering might be less noticeable when using normal incandescent bulbs, or with non-ghosting LEDs. All in all those issues appear mostly normal and expected to me in my opinion, from the description of the issues.

Good luck!

 

[lothian]

I genuinely appreciate your responses.

To clarify, the lights I observe flicker during game play are external to the pinball machine: lamps, ceiling lights, etc, To satisfy a hunch, I plugged the thing into a UPS (pretty much a line filter)--no more flickering (LED) lights on the house mains circuit during game play. This test reinforces my suspicion of the aged line filter in the cabinet.

My concern over the loud 60Hz hum at power-on reflects my naivety as a new owner of old tech. I defer to the collective experience of others. It may very well be normal.

 

[sylvain]

I see - house power goes down briefly during flipping.
Similar as when a refrigerator compressor starts, lights dim briefly, because of quick high current demand.

Changing the pinball machine's line filter will not fix dimming house lights, but feel free to try it.
I could be wrong.
The UPS has a lot more filters and internal circuits compared to the dinky passive line filter box in pinball machines.
Inductors inside that line filter box do not really age as components, in my experience.

Good luck and please keep us updated!
Cheers

 

[lothian]

Going the APC (brand) route and forsaking that anemic line filter offers benefits beyond filtering unwanted EMF and errant back voltages into the house mains. I may have stumbled onto a better solution. A call to APC product support is forthcoming.

 

[necro_nemesis]

This reminds me a I have a line stabilizer I should probably just sell since it's collecting dust.

 

[MrMikeman]

I use APC 1200W voltage regulators(I have 3):

https://www.amazon.ca/gp/product/B00009RA60/

Although I’m sure it could handle 3 games I only plug 2 in and a sub.

I like that they protect from over AND under voltage.